You need to send the midi track that you recorded into AuriaPro to the midi interface that you have your Yamaha DX7 ll pluged into. You also need to make sure that the DX7ll is receiving midi on all channels ( omni mode ). You can also send the midi on a specific midi channel as long as both the send and receive channel are the same. You will also need to take the audio out of your DX7 ll and plug it into your audio interface so that you can record the audio of the DX7 ll into AuriaPro. Cheers and good luck.